Olanzapine and Tetrabenazine Interaction

Drug interaction information between Olanzapine and Tetrabenazine.

Olanzapine and Tetrabenazine have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Olanzapine and Tetrabenazine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Olanzapine

Atypical Antipsychotic

Drug B

Tetrabenazine

VMAT2 Inhibitor

How They Interact

Both drugs lower dopamine activity in the brain, which can cause stiff muscles, tremors, or a dangerous fever.

FDA Label Information

7.6 Neuroleptic Drugs The risk for Parkinsonism, NMS, and akathisia may be increased by concomitant use of tetrabenazine and dopamine antagonists or antipsychotics (e.g., chlorpromazine, haloperidol, olanzapine, risperidone, thioridazine, ziprasidone) [see Warnings and Precautions ( 5.4 , 5.5 , 5.6 )] .

Frequently Asked Questions

What SPL severity band is on file for Olanzapine + Tetrabenazine?

Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Olanzapine has 26 labeled pairs on file vs Tetrabenazine's 16. In the moderate band specifically: Olanzapine has 1; Tetrabenazine has 9 (also Risperidone, Ziprasidone, Haloperidol, Chlorpromazine).

What mechanism field is on file for Olanzapine and Tetrabenazine?

Both drugs lower dopamine activity in the brain, which can cause stiff muscles, tremors, or a dangerous fever.

Tetrabenazine carries more major-labeled pairs than Olanzapine

SPL source-record counts only. This page's band is moderate · classes on file: Olanzapine (Atypical Antipsychotic); Tetrabenazine (VMAT2 Inhibitor).

Tetrabenazine has 2 major-labeled pairs vs Olanzapine's 1. This page itself is in the moderate band, not the major band.

Olanzapine

1 major · 1 moderate · 24 minor · 26 total

Olanzapine has no other moderate-band peer in this dataset besides Tetrabenazine.

Tetrabenazine

2 major · 9 moderate · 5 minor · 16 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.